A method for removing epitaxial films from a single crystal substrate upon which it is grown comprising (a) providing a thin release layer (≦1000A) between the film to be grown and the substrate; (b) growing the epitaxial film(s); (c) applying a polymeric support layer which is under tension over the film; and (d) selectively etching the release layer, the tension in the support layer causing the edges of the film to curve upwardly as the release layer is etched away.
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1. A process for selectively freeing an epitaxial film from a single crystal substrate upon which it was grown and comprising the steps of selectively etching away a thin release layer positioned between said film and said substrate and causing edges of said film to curl upwardly as said release layer is etched away to enhance the outdiffusion of reaction products of the etching process from the active etching area.
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1. Field of the Invention
This invention relates to epitaxially grown films and devices and more particularly to a method of releasing such films and/or devices from the single crystal substrate upon which it is formed to enable its transfer to other substrates and reuse of the single crystal substrate.
2. Description of the Prior Art
In thin film technology there has always been a tradeoff between the material quality of the film and the ease of depositing that thin film. Epitaxial films represent the highest level of quality, but they must be grown on and are accompanied by cumbersome, expensive, bulk single crystal wafer substrates. For some time, research has focused on the possibility of creating epitaxial quality thin films on arbitrary substrates while maintaining the ultimate in crystalline perfection.
The main approach has been to attempt to reuse the substrate wafer by separating it from the epitaxially grown film; however, to undercut a very thin film over its entire area without adversely affecting the film or the underlying substrate, the selectivity must be extremely high. This is very difficult to achieve. For example, J. C. Fan has described a process in which an epitaxial film is cleaved away from the substrate on which it is grown. Such change, at best, is difficult to achieve without damage to the film and/or substrate, or without removal of part of the substrate. Also, in some instances, the cleavage plane (<110>) and the growth plane (<100>) of the film may be mutually exclusive.
In a paper by Konagai et al appearing in J. of Crystal Growth 45, 277-280 (1978) it was shown that a Zn doped p-Ga1-x Alx As layer can be selectively etched from GaAs with HF. This observation was employed in the production of thin film solar cells by the following techniques. In one technique, zinc doped p-Ga1-x Alx As was grown by liquid phase epitaxy (LPE) on a n-GaAs grown layer on a GaAs single crystal substrate. During this LPE growth of the Zn doped Ga1-x Alx Asx, Zn diffuses into the surface of the underlying GaAs to form a p-type GaAs layer and hence p-n GaAs junction. The surface p-Ga1-x Alx As is then selectively etched away leaving the p-n junction GaAs layers on the GaAs substrate.
In another solar cell fabrication process Konagai et al describe a "peeled film technology". Here, a 5 micron thick Ga0.3 Al0.7 As film is epitaxially grown on a GaAs <111>substrate by LPE. A 30 micron thick Sn doped n-GaAs layer is then grown over the Ga0.3 Al0.7 As layer and a p-n junction is formed by diffusing Zn into the specimen utilizing ZnAs2 as the source of Zn. Appropriate electrical contacts are then formed on the films using known photoresist, etch and plating techniques. The surface layer is then covered with a black wax film supper layer and the wafer is soaked in an aqueous HF etchant solution. The etchants selectively dissolves the the Ga0.3 Al0.7 As layer which lies between the thin solar cell p-n junction device layers and the underlying substrate, allowing the solar cell attached to the wax to be peeled off the GaAs substrate for placement on an aluminum substrate. The wax provides support for the peeled film.
While the technique described above has been described in the literature for ten years, it was not adopted by the industry. One reason for this was a difficulty encountered in completely undercutting the Ga0.3 Al0.7 As 'release' layer in a reasonable time, especially when the area of the film to be peeled was large. This difficulty arose due to the formation and entrapment of gas, formed as a reaction product of the etching process, within the etched channel. The gas created a bubble in the channel preventing or diminishing further etching and causing cracking in the epitaxial film. The problem could only be partially obviated by using very slow reaction rates (very dilute HF solutions). Since the time required for peel-off, as well as ensuring no or minimal charge to the overlying film is important, the process was virtually abandoned.
A means for providing for the needed circulation of etchant and reaction products and the release of any gaseous reaction products of the etching process while maintaining high selectivity is therefore desired.
The present invention is directed to a process for selectively peeling an epitaxial film from a single crystal substrate upon which it was grown and to device configurations employing such peeled films.
The novel method comprises selectively etching away a thin release layer positioned between an epitaxial film and the substrate upon which it grown, while causing edges of the epitaxial film to curl upward as the release layer is etched away, thereby providing means for the escape and outdiffusion of the reaction products of the etching process from the area between the film and the substrate.
The present invention is further directed to novel structures employing such peeled film.
FIG. 1 is a side elevational view showing an epitaxially grown thin film semiconductor device being peeled from an underlying single crystal substrate by the prior art etching technique.
FIG. 2 is a side elevational view showing an epitaxially grown thin film semiconductor device being peeled from an underlying single crystal substrate by the etching technique of the present invention.
FIG. 3 is a side elevational view depicting a double heterostructure test device for measuring parameters of the films obtained from the novel lift-off process.
FIG. 4 shows the minority-carrier lifetime decay curve of the double heterostructure device of FIG. 3, both before and after lift-off, plotting carrier density (carriers/cm3) vs. time (sec.) after application of an excitation pulse.
FIGS. 5-7 show various structures of a peeled semiconductor film adhered to a glass fiber in a manner so as to provide a coupled semiconductor device-fiber structure.
The present invention is based upon the discovery of a unique means for lifting-off an epitaxial film from the substrate upon which it is grown so as to substantially eliminate the problem encountered in the past due to entrapment of gaseous reaction products in the channel formed during etching of a release layer between the film and the substrate.
In general terms, the present invention differs from the teachings of Konagai et al by providing means for lifting the edges of the epitaxial film as the release layer is selectively etched away, thereby creating a concave film surface. In this way, gaseous products of the etching reaction, which otherwise tend to accumulate in the etched channel preventing further etching and causing cracking of the epitaxial film, can now escape from the channel. The means provided for lifting the edges of the epitaxial film is a support layer over the film which is applied to the film under tension causing the film to be under compression thereby creating a concave curvature in the film as the release layer is etched away.
The principal of the invention can best be understood with reference to FIGS. 1 and 2. FIG. 1, which illustrates the prior art etch technique, shows a single crystal GaAs substrate 1 having a thin release film 2 on the surface thereof and epitaxially grown p-type and n-type GaAs layers 3 and 4, forming a p-n junction device, thereon. A support layer 5 (described as a black wax in the prior art), overlies the epitaxial layers 3 and 4. Here, as hydroflouric acid etches the release film 2 a uniformly thick channel 6 forms between the epi-layer 3 and the substrate 1. As etching progresses, the gas reaction product, which has the lowest solubility of any of the reactants or reaction products, is difficult to diffuse away thereby limiting the undercutting speed and the permissible HF acid concentration. If the solubility limits are exceeded, bubbles 7 form at the reaction zone in the channel 6 displacing the etchant and producing a gas pressure which cracks the epitaxial film. Hence, permissible acid concentrations and therefore etch speeds are very low.
In comparison, FIG. 2 shows the results of the novel technique employing the same structure, but where a support layer 25 is applied so as to be under tension such that as undercutting of the release layer 2 occurs, the film curls with a radius of curvature R thereby forming a non-uniform channel 26 which is wider at the edges than the center of the film.
We have calculated the maximum permissible speed of undercutting for the case of the prior art plane parallel etching 6. Equating the diffusion flux with the etching flux: ##EQU1## where v is the etching speed, n and N are the molar concentrations of dissolved gas and release layer (e.g. AlAs) respectively, t is the thickness of the channel, D is the diffusion constant of the gas, and z is the position coordinate down the channel. It is assumed that 3 moles of gas are produced for every mole of AlAs. By making this calculation, we see that thickness cancels from both sides of the equation, hence, contrary to intuition, a thick release layer which leads to a wider channel does not overcome the mass transport problem since proportionately more gas must be removed. Integrating equation (1) down a plane parallel channel of depth L results in a maximum undercutting speed v:
v=Dn/3LN (2)
where n is now the saturation solubility of the gas. For an AlAs or a Alx Ga1-x As release layer where x is from 0.5 to 1, n/N is approximately 2×10-5 and D in aqueous media is about 5×10-5 cm2 /sec. Hence, the speed of removal of the release layer is severely limited in channels of any significant depth. However, if the channel opens up by virtue of the curvature shown in FIG. 2, then the outdiffusion becomes much easier.
Equating again, the etching flux with the diffusion flux for the novel method as depicted with reference to FIG. 2: ##EQU2## where R is the radius of curvature induced by the tension in the support layer. Integrating this equation we get ##EQU3## Comparing equations (2) and (4) it can be seen that the effective depth "L" of the channel is fixed at a small value π.sqroot.Rt/2 roughly the geometric mean of R and t and independent of the actual depth. Since t is a microscopic quantity representing the thickness of the release layer, and the radius of curvature, R, is typically a few centimeters, L can be as little as 30 microns even when the actual channel depth is one hundred times deeper. Hence, we have found that contrary to intuition, using the novel method, the need to transport reaction product away from the etching zone (the interface) of acid and release layer) one should make the release layer as thin as possible. Typically, we have employed release layers of less than 1000 A in thickness and some as thin as 20 A.
After etching is complete, the epitaxial layers remain supported by the support layer and may be transferred to another substrate leaving the expensive single crystal original substrate available for re-use.
The films may be adhered to the new substrate, e.g. glass, diamond, silica, quartz, metal, etc. by bonding the film e.g. with an ultraviolet curable cement of the type used to splice optical fibers and as is known in that art of with other compatible adhesives. In this way, a permanent support for large area crack free, peeled films can be made.
Alternatively, we have discovered that GaAs epitaxial films, for example, can be directly "optical contacted" to certain substrates, e.g. glass or silicon due to strong Van Der Waals forces bonding the surfaces of the film to the substrate without the need for adhesives. The support layer can be washed away with an appropriate solvent.
In order to determine the material quality and the etching characteristics, measurements of contactless minority-carrier lifetime decay was taken employing a double heterostructure as shown in FIG. 3. In accordance with this structure, a release layer 32 having a thickness of about 1000 A (can be as little as 20 A) is grown on a GaAs:Cr substrate 31. A 500 A thick GaAs epitaxial layer 33 is formed over the release layer 32 followed by epitaxial layers 34, 35 and 36 consisting of Alx Ga1-x As (5,000 A), GaAs (2 μm), and Alx Ga1-x As (5,000 A)m respectively wherein x ≦0.4. A support layer 35, under tension, is provided over the top Alx Ga1-s As layer. The minority-carrier lifetime in this structure may be very long. A surface layer of Ga1-x Alx As as thin as 100 A is able to confine the minority-carriers within the GaAs layer 35 potential well. When the upper Alx Ga1-x As layer is etched away, the minority-carrier lifetime becomes very short due to surface recombination. Therefore, the structure permits a sensitive measure of very small etch rates.
By monitoring the minority-carrier lifetime of the GaAs potential well capped by the thin Alx Ga1-x As layers as a function of etch time and of composition x, we determined some of these important parametric dependences. We found that the etch rate of Al0.4 Ga0.6 As in concentrated (48%) HF acid could be very slow, only ≈1.5 A per hour, at room temperature and even slower at 0° C. We must assume that the etch rate of pure GaAs is yet again slower. By contrast, an increase in aluminum concentration from 40 to 50% increases the etch rate by many orders of magnitude. Based upon the speed at which the AlAs release layers are undercut, the etch rate can be as high as 1 mm per hour (depending upon and roughly proportional to HF acid concentration). Such a degree of selectivity (≧107) might be associated with percolation type behavior or possibly a shift from T minimum to X-point minimum in the band structure. In optimizing the lift-off process we standardized the release layer composition to pure AlAs but Alx Ga1-x As layers where x is ≧0.5 were equally successful.
The films were grown on <100> oriented GaAs substrates by molecular beam epitaxy and organometallic chemical vapor deposition. The superb electronic quality of epitaxially grown films is unaffected by the lift-off process. This may be seen from the minority-carrier lifetime decay curves shown in FIG. 4. Minority-carrier lifetime is one of the best measures of crystalline perfection and purity. The test structure shown in FIG. 3 was monitored by a contactless lifetime probe technique as is known in the art. For comparison, the carrier density decay curve was measured before lift-off and then again after lift-off. The two decays overlay identically so there is only one curve actually shown in FIG. 4. This indicates that the peeled film did not suffer any damage or cracking with the novel process. The initial rapid decay is due to radiative electronhole recombination, and the slow decay at lower density measures the Shockley-Read-Hall lifetime.
In accordance with the novel process, a solution, e.g., 25 grams of support layer material in 100 ml solvent is sprayed onto a finished GaAs wafer having the epitaxially grown release layer and device layers thereon through a shadow mask and the solvent is evaporated. This is done several times to build up the support layer thickness. A preferred support layer material is a polymeric material known as Apiezon W which is readily soluble in trichloroethylene. This material is a mixture consisting of 62% paraffinic hydrocarbon polymer and 38% asphaltene hydrocarbons. Typically the thickness of the support layer is from 0.1 mm to 1 mm.
The support layer is then air cured for about 1/2 hour and the wafer is then placed in an oven at about 100°C for about 1/2 hour to cure the support layer. This heating process produces the tension which causes the curvature upon etching of the release layer. The epitaxial layer edges around the support layer are then exposed by removing the support layer from around the edges with a solvent and then etching non-selectively or by cleavage. The same is then placed in HF acid solution. Typically, 10% HF acid concentrations are employed, concentrated HF being a 48% solution. The sample is allowed to sit in the HF for up to about 24 hours and the GaAs epitaxial film supported by the support layer simply floats off or is detached from the substrate. The film may then be removed and adhered to any other desired substrate.
We have also discovered that the selectivity of etching of the release layer can be enhanced if etching is accomplished at reduced temperatures, e.g. about 0°C
While Apiezon W is a preferred support layer which when treated as stated gives the desired result, it will be obvious to those skilled in the art that the support layer may be any polymeric material, which is cured or further cured after adhering it to the surface of the film to be removed such that the bonds formed upon curing are under tension due to adhesion to the film.
It should be understood that the epitaxial film being removed may be a single layer or multiple epitaxial layers and metallized to provide means for making electrical contact thereto and forming a semiconductor device. It should be further understood that the concept described herein is not limited to any particular semiconductor material, release layer or support layer and the principles can be employed with any compatible layers wherein a release layer can be selectively etched and undercut from between a single substrate and a overlying epitaxial semiconductor layer.
The novel process described above allows one to make structures employing epitaxial films which otherwise have not been possible. For example, a free epitaxial film comprising layers forming a light emitting diode, a laser, a photodetector or a photovoltaic device 51 may be directly adhered to an optical fiber or fiber bundle 52 as depicted in FIGS. 5-7 by means of an adhesive or by an adhesiveless optical contact using Van der Waals forces as previously described. Such structures will eliminate and/or reduce the problems of optical coupling normally associated with such devices in optical systems.
A particularly suitable choice for coupling with an optical fiber or alternatively, for placement on a conductive substrate, is a peeled film having a plurality of epitaxially grown doped and/or intrinsic layers of Inx Ga1-x Asy P1-y wherein x and y can vary from 0 to 1 to produce a laser device. Such Inx Ga1-x Asy P1-y lasers are well known in the art and are generally formed by molecular beam epitaxial growth of the layers on an InP substrate. Here, a thin (20A-100A) strained AlAs release layer is employed between the substrate and the active device layers and the film is peeled in accordance with the teachings of the present invention.
Yablonovitch, Eli, Gmitter, Thomas J.
| Patent | Priority | Assignee | Title |
| 10204831, | Dec 17 2008 | UTICA LEASECO, LLC ASSIGNEE | Tape-based epitaxial lift off apparatuses and methods |
| 10259206, | Mar 02 2010 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off systems and methods |
| 10923617, | Jul 03 2007 | MicroLink Devices, Inc. | Methods for fabricating thin film III-V compound solar cell |
| 11177498, | Oct 15 2018 | AMPCERA INC | Redox flow batteries, components for redox flow batteries and methods for manufacture thereof |
| 11393683, | Oct 14 2009 | UTICA LEASECO, LLC ASSIGNEE | Methods for high growth rate deposition for forming different cells on a wafer |
| 11600853, | May 14 2019 | AMPCERA INC | Systems and methods for storing, transporting, and handling of solid-state electrolytes |
| 11819806, | Oct 15 2018 | AMPCERA INC | Methods for manufacturing a solid state ionic conductive membrane on a macro porous support scaffold |
| 11901476, | Jul 03 2007 | MicroLink Devices, Inc. | Methods for fabricating thin film III-V compound solar cell |
| 12154702, | Oct 15 2018 | AMPCERA INC | Methods for manufacturing a freestanding solid state ionic conductive membrane |
| 5122852, | Apr 23 1990 | TTI Inventions A LLC | Grafted-crystal-film integrated optics and optoelectronic devices |
| 5201996, | Apr 30 1990 | TTI Inventions A LLC | Patterning method for epitaxial lift-off processing |
| 5206749, | Dec 31 1990 | KOPIN CORPORATION, A CORP OF DE | Liquid crystal display having essentially single crystal transistors pixels and driving circuits |
| 5207864, | Dec 30 1991 | HEREFORD CORONADO, LLC | Low-temperature fusion of dissimilar semiconductors |
| 5209815, | Jun 06 1991 | International Business Machines Corporation | Method for forming patterned films on a substrate |
| 5221637, | May 31 1991 | Interuniversitair Micro Elektronica Centrum vzw | Mesa release and deposition (MRD) method for stress relief in heteroepitaxially grown GaAs on Si |
| 5236871, | Apr 29 1992 | The United States of America as represented by the Administrator of the | Method for producing a hybridization of detector array and integrated circuit for readout |
| 5256562, | Dec 31 1990 | Kopin Corporation | Method for manufacturing a semiconductor device using a circuit transfer film |
| 5258320, | Dec 31 1990 | Kopin Corporation | Single crystal silicon arrayed devices for display panels |
| 5258325, | Dec 31 1990 | KOPIN CORPORATION, A CORP OF DE | Method for manufacturing a semiconductor device using a circuit transfer film |
| 5261969, | Apr 14 1992 | Boeing Company | Monolithic voltage-matched tandem photovoltaic cell and method for making same |
| 5262347, | Aug 14 1991 | STANFORD UNIVERSITY OTL, LLC | Palladium welding of a semiconductor body |
| 5265107, | Feb 05 1992 | STANFORD UNIVERSITY OTL, LLC | Broadband absorber having multiple quantum wells of different thicknesses |
| 5268065, | Dec 21 1992 | Apple Inc | Method for thinning a semiconductor wafer |
| 5276345, | Oct 30 1992 | California Institute of Technology | Composite GaAs-on-quartz substrate for integration of millimeter-wave passive and active device circuitry |
| 5277749, | Oct 17 1991 | INTERNATIONAL BUSINESS MACHINES CORPORATION A CORPORATION OF NEW YORK | Methods and apparatus for relieving stress and resisting stencil delamination when performing lift-off processes that utilize high stress metals and/or multiple evaporation steps |
| 5286335, | Apr 08 1992 | Georgia Tech Research Corporation; GEORGIA TECH RESEARCH CORPORATION A CORPORATION OF GA | Processes for lift-off and deposition of thin film materials |
| 5300788, | Jan 18 1991 | KOPIN CORPORATION A CORP OF DELAWARE | Light emitting diode bars and arrays and method of making same |
| 5302842, | Jul 20 1992 | STANFORD UNIVERSITY OTL, LLC | Field-effect transistor formed over gate electrode |
| 5334283, | Aug 31 1992 | The University of North Carolina at Chapel Hill | Process for selectively etching diamond |
| 5344517, | Apr 22 1993 | OPTICAL COMMUNICATION PRODUCTS, INC | Method for lift-off of epitaxial layers and applications thereof |
| 5362671, | Dec 31 1990 | Kopin Corporation | Method of fabricating single crystal silicon arrayed devices for display panels |
| 5376229, | Oct 05 1993 | Agilent Technologies Inc | Method of fabrication of adjacent coplanar semiconductor devices |
| 5376561, | Dec 31 1990 | KOPIN CORPORATION, A DE CORP | High density electronic circuit modules |
| 5376580, | Mar 19 1993 | Lumileds LLC | Wafer bonding of light emitting diode layers |
| 5377031, | Dec 31 1990 | Kopin Corporation | Single crystal silicon tiles for liquid crystal display panels including light shielding layers |
| 5401665, | Jul 20 1992 | STANFORD UNIVERSITY OTL, LLC | Method of fabricating a field-effect transistor over gate electrode |
| 5401983, | Apr 08 1992 | Georgia Tech Research Corporation | Processes for lift-off of thin film materials or devices for fabricating three dimensional integrated circuits, optical detectors, and micromechanical devices |
| 5453405, | Jan 18 1991 | Kopin Corporation | Method of making light emitting diode bars and arrays |
| 5458694, | Apr 15 1992 | Picogiga Societe Anonyme | Multispectral photovoltaic component comprising a stack of cells, and method of manufacture |
| 5465009, | Apr 08 1992 | Georgia Tech Research Corporation | Processes and apparatus for lift-off and bonding of materials and devices |
| 5476810, | Jan 31 1994 | U.S. Philips Corporation | Manufacture of electronic devices comprising thin-film circuits using a metal foil as a temporary support |
| 5479043, | Apr 15 1992 | Picogiga Societe Anonyme | Multispectral photovoltaic component |
| 5528397, | Dec 03 1991 | Kopin Corporation | Single crystal silicon transistors for display panels |
| 5539550, | Dec 31 1990 | Kopin Corporation | Liquid crystal display having adhered circuit tiles |
| 5546375, | Jul 15 1992 | Hynix Semiconductor Inc | Method of manufacturing a tip for scanning tunneling microscope using peeling layer |
| 5620557, | Jun 26 1995 | TOYODA GOSEI CO , LTD ; AKASAKI, ISAMU; AMANO, HIROSHI | Sapphireless group III nitride semiconductor and method for making same |
| 5641381, | Mar 27 1995 | The United States of America as represented by the Administrator of the | Preferentially etched epitaxial liftoff of InP material |
| 5702963, | Dec 31 1990 | Kopin Corporation | Method of forming high density electronic circuit modules |
| 5757445, | Dec 31 1990 | Kopin Corporation | Single crystal silicon tiles for display panels |
| 6043800, | Dec 31 1990 | Kopin Corporation | Head mounted liquid crystal display system |
| 6114188, | Apr 12 1996 | Northeastern University | Method of fabricating an integrated complex-transition metal oxide device |
| 6143582, | Dec 31 1990 | Kopin Corporation | High density electronic circuit modules |
| 6187653, | Dec 17 1999 | AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LIMITED | Method for attractive bonding of two crystalline substrates |
| 6214733, | Nov 17 1999 | ELO TECHNOLOGIES, INC | Process for lift off and handling of thin film materials |
| 6232136, | Dec 31 1990 | Kopin Corporation | Method of transferring semiconductors |
| 6287891, | Apr 05 2000 | HRL Laboratories, LLC | Method for transferring semiconductor device layers to different substrates |
| 6312304, | Dec 15 1998 | E Ink Corporation | Assembly of microencapsulated electronic displays |
| 6346459, | Feb 05 1999 | SILICON WAFER TECHNOLOGIES, INC | Process for lift off and transfer of semiconductor devices onto an alien substrate |
| 6352909, | Jan 06 2000 | SILICON WAFER TECHNOLOGIES, INC | Process for lift-off of a layer from a substrate |
| 6387829, | Jun 18 1999 | SILICON WAFER TECHNOLOGIES, INC | Separation process for silicon-on-insulator wafer fabrication |
| 6403985, | Jan 18 1991 | Kopin Corporation | Method of making light emitting diode displays |
| 6414783, | Dec 31 1990 | Kopin Corporation | Method of transferring semiconductors |
| 6424020, | Dec 31 1990 | Kopin Corporation | High Density electronic circuit modules |
| 6436614, | Oct 20 2000 | Phosistor Technologies, Incorporated | Method for the formation of a thin optical crystal layer overlying a low dielectric constant substrate |
| 6445489, | Mar 18 1998 | E Ink Corporation | Electrophoretic displays and systems for addressing such displays |
| 6473072, | May 12 1998 | E Ink Corporation | Microencapsulated electrophoretic electrostatically-addressed media for drawing device applications |
| 6486929, | Dec 31 1990 | Kopin Corporation | Bonded layer semiconductor device |
| 6498114, | Apr 09 1999 | E Ink Corporation | Method for forming a patterned semiconductor film |
| 6504524, | Mar 08 2000 | E Ink Corporation | Addressing methods for displays having zero time-average field |
| 6518949, | Apr 10 1998 | E Ink Corporation | Electronic displays using organic-based field effect transistors |
| 6521940, | Dec 31 1990 | Kopin Corporation | High density electronic circuit modules |
| 6531997, | Apr 30 1999 | E Ink Corporation | Methods for addressing electrophoretic displays |
| 6559075, | Oct 01 1996 | Siemens Aktiengesellschaft | Method of separating two layers of material from one another and electronic components produced using this process |
| 6589811, | Apr 05 2000 | HRL Laboratories, LLC | Method for transferring semiconductor device layers to different substrates |
| 6593978, | Dec 31 1990 | Kopin Corporation | Method for manufacturing active matrix liquid crystal displays |
| 6627953, | Dec 31 1990 | Kopin Corporation | High density electronic circuit modules |
| 6669801, | Jan 21 2000 | Fujitsu Limited | Device transfer method |
| 6683333, | Jul 14 2000 | E INK | Fabrication of electronic circuit elements using unpatterned semiconductor layers |
| 6738050, | May 12 1998 | E Ink Corporation | Microencapsulated electrophoretic electrostatically addressed media for drawing device applications |
| 6740604, | Oct 01 1996 | Siemens Aktiengesellschaft | Method of separating two layers of material from one another |
| 6809044, | Jun 30 1999 | Commissariat a l'Energie Atomique | Method for making a thin film using pressurization |
| 6839158, | Aug 27 1997 | E Ink Corporation | Encapsulated electrophoretic displays having a monolayer of capsules and materials and methods for making the same |
| 6842657, | Apr 09 1999 | E Ink Corporation | Reactive formation of dielectric layers and protection of organic layers in organic semiconductor device fabrication |
| 6900851, | Feb 08 2002 | E Ink Corporation | Electro-optic displays and optical systems for addressing such displays |
| 6916584, | Aug 01 2002 | CITIBANK, N A | Alignment methods for imprint lithography |
| 6919935, | Dec 31 1990 | Kopin Corporation | Method of forming an active matrix display |
| 6921615, | Jul 16 2000 | Board of Regents, The University of Texas Systems | High-resolution overlay alignment methods for imprint lithography |
| 6929762, | Nov 13 2002 | CITIBANK, N A | Method of reducing pattern distortions during imprint lithography processes |
| 6943050, | Jul 11 2002 | Seiko Epson Corporation | Method for making semiconductor device, semiconductor element composite, electro-optical apparatus, and electronic system |
| 6967640, | Jul 27 2001 | E Ink Corporation | Microencapsulated electrophoretic display with integrated driver |
| 6972051, | Jan 27 1994 | WOLFSPEED, INC | Bulk single crystal gallium nitride and method of making same |
| 6974758, | Oct 01 1996 | Siemens Aktiengesellschaft | Method of producing a light-emitting diode |
| 6990870, | Dec 12 2002 | CITIBANK, N A | System for determining characteristics of substrates employing fluid geometries |
| 7030412, | May 05 1999 | E Ink Corporation | Minimally-patterned semiconductor devices for display applications |
| 7045878, | May 18 2001 | USPTO; Reveo, Inc | Selectively bonded thin film layer and substrate layer for processing of useful devices |
| 7077992, | Jul 11 2002 | CITIBANK, N A | Step and repeat imprint lithography processes |
| 7081657, | May 18 2001 | Reveo, Inc. | MEMS and method of manufacturing MEMS |
| 7122079, | Feb 27 2004 | CITIBANK, N A | Composition for an etching mask comprising a silicon-containing material |
| 7136150, | Sep 25 2003 | CITIBANK, N A | Imprint lithography template having opaque alignment marks |
| 7145219, | Sep 12 2001 | Reveo, Inc. | Vertical integrated circuits |
| 7153761, | Oct 03 2005 | SHENZHEN XINGUODU TECHNOLOGY CO , LTD | Method of transferring a thin crystalline semiconductor layer |
| 7157036, | Jun 17 2003 | CITIBANK, N A | Method to reduce adhesion between a conformable region and a pattern of a mold |
| 7163826, | Sep 12 2001 | Reveo, Inc | Method of fabricating multi layer devices on buried oxide layer substrates |
| 7176880, | Jul 21 1999 | E Ink Corporation | Use of a storage capacitor to enhance the performance of an active matrix driven electronic display |
| 7198671, | Jul 11 2001 | Matsushita Electric Industrial Co., Ltd.; MATSUSHITA ELECTRIC INDUSTRIAL CO , LTD | Layered substrates for epitaxial processing, and device |
| 7202141, | Mar 29 2004 | IPG Photonics Corporation | Method of separating layers of material |
| 7229901, | Dec 16 2004 | Wisconsin Alumni Research Foundation | Fabrication of strained heterojunction structures |
| 7241667, | Mar 29 2004 | IPG Photonics Corporation | Method of separating layers of material |
| 7242513, | Aug 28 1997 | E Ink Corporation | Encapsulated electrophoretic displays having a monolayer of capsules and materials and methods for making the same |
| 7332031, | Jan 27 1994 | WOLFSPEED, INC | Bulk single crystal gallium nitride and method of making same |
| 7341925, | Oct 01 1996 | Osram GmbH | Method for transferring a semiconductor body from a growth substrate to a support material |
| 7382363, | Jul 27 2001 | E Ink Corporation | Microencapsulated electrophoretic display with integrated driver |
| 7452574, | Feb 27 2003 | CITIBANK, N A | Method to reduce adhesion between a polymerizable layer and a substrate employing a fluorine-containing layer |
| 7638410, | Oct 03 2005 | Los Alamos National Security, LLC | Method of transferring strained semiconductor structure |
| 7713840, | Oct 01 1996 | Osram GmbH | Electronic components produced by a method of separating two layers of material from one another |
| 7736996, | Apr 15 2005 | SHENZHEN XINGUODU TECHNOLOGY CO , LTD | Method for damage avoidance in transferring an ultra-thin layer of crystalline material with high crystalline quality |
| 7777290, | Jun 13 2006 | Wisconsin Alumni Research Foundation | PIN diodes for photodetection and high-speed, high-resolution image sensing |
| 7794542, | Jan 27 1994 | WOLFSPEED, INC | Bulk single crystal gallium nitride and method of making same |
| 7803308, | Dec 01 2005 | CITIBANK, N A | Technique for separating a mold from solidified imprinting material |
| 7859637, | Jul 21 1999 | E Ink Corporation | Use of a storage capacitor to enhance the performance of an active matrix driven electronic display |
| 7906180, | Feb 27 2004 | CITIBANK, N A | Composition for an etching mask comprising a silicon-containing material |
| 7960218, | Sep 08 2006 | Wisconsin Alumni Research Foundation | Method for fabricating high-speed thin-film transistors |
| 7968355, | Apr 25 2008 | Samsung Electronics Co., Ltd.; SAMSUNG ELECTRONICS CO , LTD | Luminous devices, packages and systems containing the same, and fabricating methods thereof |
| 7973336, | Dec 16 2004 | Wisconsin Alumni Research Foundation | Released freestanding strained heterojunction structures |
| 8003492, | May 30 2008 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off stack having a unidirectionally shrunk handle and methods thereof |
| 8008174, | Oct 10 2008 | UTICA LEASECO, LLC ASSIGNEE | Continuous feed chemical vapor deposition |
| 8076386, | Feb 23 2004 | CITIBANK, N A | Materials for imprint lithography |
| 8174030, | Apr 25 2008 | Samsung Electronics Co., Ltd. | Luminous devices, packages and systems containing the same, and fabricating methods thereof |
| 8198148, | Dec 07 2009 | Electronics and Telecommunications Research Institute | Method for manufacturing semiconductor device |
| 8278668, | Apr 25 2008 | Samsung Electronics Co., Ltd. | Luminous devices, packages and systems containing the same, and fabricating methods thereof |
| 8309432, | May 30 2008 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off stack having a universally shrunk handle and methods thereof |
| 8314011, | May 30 2008 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off stack having a non-uniform handle and methods thereof |
| 8349241, | Oct 04 2002 | CITIBANK, N A | Method to arrange features on a substrate to replicate features having minimal dimensional variability |
| 8362592, | Feb 27 2009 | UTICA LEASECO, LLC ASSIGNEE | Tiled substrates for deposition and epitaxial lift off processes |
| 8367518, | May 30 2008 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off stack having a multi-layered handle and methods thereof |
| 8492245, | Feb 07 2012 | Wisconsin Alumni Research Foundation | Methods for making thin layers of crystalline materials |
| 8602707, | May 30 2008 | UTICA LEASECO, LLC ASSIGNEE | Methods and apparatus for a chemical vapor deposition reactor |
| 8614450, | Apr 25 2008 | Samsung Electronics Co., Ltd. | Luminous devices, packages and systems containing the same, and fabricating methods thereof |
| 8657994, | Apr 01 2011 | Alta Devices, Inc | System and method for improved epitaxial lift off |
| 8716107, | May 30 2008 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off stack having a non-uniform handle and methods thereof |
| 8748324, | Feb 26 2013 | The Boeing Company | Systems and methods for separating components of a multilayer stack of electronic components |
| 8778199, | Feb 09 2009 | SOLAERO TECHNOLOGIES CORP | Epitaxial lift off in inverted metamorphic multijunction solar cells |
| 8937321, | Apr 25 2008 | Samsung Electronics Co., Ltd. | Luminous devices, packages and systems containing the same, and fabricating methods thereof |
| 9064810, | Oct 10 2008 | UTICA LEASECO, LLC ASSIGNEE | Mesa etch method and composition for epitaxial lift off |
| 9068278, | Dec 08 2008 | UTICA LEASECO, LLC ASSIGNEE | Multiple stack deposition for epitaxial lift off |
| 9070764, | May 30 2008 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off stack having a pre-curved handle and methods thereof |
| 9142707, | Apr 01 2011 | UTICA LEASECO, LLC ASSIGNEE | System and method for improved epitaxial lift off |
| 9165805, | Dec 17 2008 | UTICA LEASECO, LLC ASSIGNEE | Tape-based epitaxial lift off apparatuses and methods |
| 9223202, | Jul 17 2000 | CITIBANK, N A | Method of automatic fluid dispensing for imprint lithography processes |
| 9287479, | Apr 25 2008 | Samsung Electronics Co., Ltd. | Luminous devices, packages and systems containing the same, and fabricating methods thereof |
| 9340895, | Jun 27 2013 | The Boeing Company | Systems and methods for separating components of a multilayer stack of electronic components |
| 9381731, | Mar 02 2010 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off systems and methods |
| 9458550, | Feb 26 2013 | The Boeing Company | Systems and methods for separating components of a multilayer stack of electronic components |
| 9522521, | Apr 23 2012 | Nanyang Technological University | Apparatus and method for separating a stacked arrangement |
| 9679814, | May 30 2008 | UTICA LEASECO, LLC ASSIGNEE | Epitaxial lift off stack having a pre-curved handle and methods thereof |
| 9834860, | Oct 14 2009 | UTICA LEASECO, LLC ASSIGNEE | Method of high growth rate deposition for group III/V materials |
| 9876066, | May 15 2012 | Nanyang Technological University | Device and structure and method for forming the same |
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